A eukaryotically conserved protein complex; in humans, it is comprised of LAMTOR1, LAMTOR2, LAMTOR3, LAMTOR4, and LAMTOR5. The complex is anchored to lipid rafts in late endosome membranes via LAMTOR1, constitutes a guanine nucleotide exchange factor (GEF) for the Rag GTPases. [ http://www.ncbi.nlm.nih.gov/pubmed/19177150 http://www.ncbi.nlm.nih.gov/pubmed/20381137 http://www.ncbi.nlm.nih.gov/pubmed/22980980 http://www.ncbi.nlm.nih.gov/pubmed/29199950 ]